d100 dice - Basic mesh to start
You can't get a 100 faces icosphere. At subdiv 2 you've got 80 faces, and at subdiv 3 you've got 320 faces.

What you can do is add a subdiv 3 icosphere, then add a Decimate modifier to it. Adjust the Ratio parameter until Face Count is 100. That wont be a nice dice however, cause some faces will be larger than others, and with different forms, so the odds of each face wont be equal.

This set include a D100, maybe you could use it as a base.